Analysis of the molecular dynamics of catecholamine storage vesicles is important understanding the mechanisms of catecholamine synthesis, exocytois and neurotransmission. Dopamine Beta-monooxygenase (D Beta H) catalyzes the synthesis of the hormone-neurotransmitter noradrenaline storage vesicles of the adrenal medulla (chromaffin granules) or the neuron (synaptic vesicles). D Beta H is a tetramer (280,000 MW) of four identical unit (74,000 MW). The determination of the amino acid sequence of the soluble D Beta H subunit will be completed using strategies of cleavage and fragmentation designed to efficiently use high sensitiviy automatic sequencing techniques. Membrane-bound D Beta H will be solubilized and purified in order to compare its amino acid and carbohydrate content and its primary structure to soluble D Beta H. The protein topography of the chromaffin granule membrane will be explored using radioactive labeling and enzymatic procedures in order to elucidate the physical relationship of D Beta H to the membrane and to the other membrane proteins. Chemical modification experiments will be designed to study D Beta H subunit interaction, D Beta H-membrane relationship and active site residues. Spectral analysis, molecular weight determinations and partial sequence determination of the granule soluble lipoprotein will be performed in order to assess the extent of similarities to known lipoproteins. These studies will contribute to the understanding of D Beta H and its subcellular milieu.